146 TRUE LONGITUDE OF A PLANET Further instructions relating to mandakarna and sighrakarna : 55. When the Rsine of the greatest correction (antyaphala) is to be subtracted from the Rsine of the koti (due to the kendra), but subtraction is not possible, then subtract reversely (i. e., the latter from the former). Determine the mandakarna by the method of successive approximations (as in the case of the Sun or Moon) and the sighrakarna by a single application of the process (as taught in stanza 47). In the case of the mandakarna, the Rsine of the greatest correction is equal to the radius of the corrected manda epicycle, i.e., to (corrected manda epicycle) x R 80 and in the case of the sighrakarna, the greatest correction is equal to the radius of the corrected sighra epicycle, i.e., to (corrected sighra epicycle) XR 80 A rule pertaining to the direct and retrograde motions of a planet : 56-57. Having applied to the longitude of the sighrocca half the difference between the true and mean longitudes (of a planet) positively or negatively, depending upon (whether) the mean longitude (of the planet is greater or less than the true longitude), determine whether the motion of the planet is vakra or ativakra or whether it is the end of the vakra motion. The true longitude of the planet having been subtracted from the longitude of the (corrected) sighrocca, when the diffe- rence is 4 signs, the planet is about to take up vakra (retrograde) motion; when 6 signs, it is in ativakra (maximum retrograde) motion; and when ³8 signs, it soon abandons the regressive path.* The difference between the true longitudes of a planet computed for (sunrise ohj the day to'elapse (i.e., today) and ¹ Reference is to the rule given in stanza 47.
- This rule is found also in Sise, iii. 59 BrSpSi, ii, 50-51; ŠiDV, I,
'ii. -42.
